I'm going to try giving you guys a brief look into India's culture and traditions by addressing certain stereotypes, and I hope it clears some questions you might have. (Most of this is based on personal experience, so feel free to add to your own comments.)
1. Everyone in India speaks Hindi.
India has 29 states. It also has 22 officially recognized languages and many more dialects spread across the states. Our states were ligustically demarcated initally, so most people in a state know a common language (but with migration towards cities, this is slowly changing).
2. Everyone in India follows Hinduism.
India has a pretty unique blend of people from all religions. Hindus form the majority group, but there are also Muslims, Christians, Sikhs, Jains, Jews, etc.
Hinduism is a polytheistic religion, which means we worship more than one God. Common Hindu festivals are: Holi (Festival of Colors) and Diwali (Festival of Lights). There are similarities in the way they are celebrated across the nation (throwing colors at each other, lighting firecrackers) but there are also certain differences that can be observed from state to state.
P.S: There also quite a few atheists or agnostics in my generation.
3. All teenagers are encouraged to engineers and doctors.
It is true that the Sciences are given much more emphasis in our Nation, as one factor that motivates parents in our country is poverty. Parents are often convinced that a stable, well-paying career can be found in the Engineering or Medicine, which is why they do keep these options in mind for their child's future.
Since our country is slowly developing, ackowledgment is now given to the Arts (especially in urban areas, where children from higher economic backgrounds have a wider choice regarding the subjects and colleges they want). Contrary to popular opinion, not all Indian are Science and Math nerds.
4. Indian cuisine is about chicken curry and naan.
A pet peeve of mine is when people write about their characters getting Indian take-out and the only two dishes present are the ones mentioned above. Indian cuisine is so diverse!
One interesting aspect of it is how religion and regions influence cooking. Most Hindus for example, usually avoid non-veg food (especially beef). The Northern part of the country is know for Roti, Naan curries and rice dishes like Biryani, while the Southern part is known for dishes like Dosa, Idli, Vada, etc. Indian dishes are known for various spices and herbs, but they can also be rather mild. Indian sweets are also diverse and usually cooked with Ghee (home-made butter).
Do look up more about Indian dishes if you're interested!
5. Indians have a heavy, obnoxious accent.
A lot of people form ideas about Indian accents from shows like The Big Bang Theory and The Simpsons. Not all of us sound like Raj or Apu, trust me on this. As English is not our first language, the way some of pronounce words might be different, but it is insulting to insinuate that we sound exactly like these characters with exaggerated accents.
6. We wear saris to parties.
Firstly, we have other traditional wear (like kurtas, ghaghra-cholis etc). Secondly, saris are difficult to wear and handle, which is why they are usually reserved for important festivals. We also wear jeans, skirts and dresses more often than people think we do.
7. We love Bollywood.
Many teenagers living in cities cringe at mainstream Bollywood movies (especially the song-and-dance ones). The rising popularity of Pretentious Movie Reviews on Youtube supports this trend. This doesn't mean that Bollywood doesn't produce quality content, just that people are starting to critique movies more.
In conclusion, if you're writing an Indian character, please do some research instead of following stereotypes or basing them on popular characters in Western media, who could use some work. For example: Alex Parrish in Quantico. Personally I would've preferred an Indian name for an Indian actress. It's kind of sloppy to make your cast diverse, but put no effort in choosing a name that acknowledges the character's background.
Google will provide large amounts of information, and if you need an Indian's perspective, I'm always willing to help. There are 1.2 billion of us, and we deserve to be represented well.